In the construction of diesel engines, particularly diesel engines of earthworking machines, space is severely limited for locating and positioning various components of the engine and components associated with the engine. It has also been a problem to maintain actuating fluid lines which power the fuel injectors filled to capacity during periods when the engine is shut down for an extended period and/or during cold weather conditions. During such times, actuating fluid occasionally drains out of the system and/or the volume of actuating fluid decreases in response to cooling thereof. This reduction in the volume of actuating fluid can result in the introduction of air into the system, leading to an undesirable increase in cranking times during cold-weather starts. In order to overcome this problem, actuating fluid must be supplied to the system so that sufficient pressure can be developed to inject fuel into the combustion chambers and start the engine.
Glassey, U.S. Pat. No. 5,213,083, assigned to the assignee of the instant application, discloses a hydraulically actuated fuel injection system including a high pressure actuating fluid pump for developing high pressure actuating fluid for fuel injectors and a priming reservoir arranged in fluid communication between a sump and an inlet of the pump. The priming reservoir primes and thereby facilitates rapid pressurization of the high pressure pump during engine start-up so that long cranking times are avoided. In addition, means are provided for automatically making up or replenishing voids in manifolds downstream of the pump due to cooling and contraction of actuating fluid and/or precipitation of entrained air from the actuating fluid. Such means comprises an actuating fluid siphon passage having a check valve therein which bypasses the inlet of the high pressure pump and is connected directly between the priming reservoir and the manifolds.
While the fuel injection system disclosed in the above-identified Glassey '083 patent is effective to limit cranking times, it is necessary that the lowest level of the actuating fluid in the reservoir be higher than the pump inlet. In installations where sufficient space above the pump mounting location is not available or in a situation where the pump mounting location is at a low elevation compared to the engine head and injectors, the system disclosed in Glassey '083 patent may not be suitable.
The present invention is directed to overcoming one or more of the problems as set forth above.